Gavin went on 24 runs last month that totaled 100 miles. Each run was a distance of either 3 miles or 5 miles. Which system of equations can be used to determine the number of 3-mile runs, x, and the number of 5-mile runs, y, that Gavin went on last month? A.
x + y = 100
3x + 5y = 24

B.
x + y = 100
5x + 3y = 24

C.
x + y = 24
3x + 5y = 100

D.
x + y = 24
5x + 3y = 100

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.

Equatorial triangle and obtuce angle